Science: Technoquest

Q Life, the universe and everything. The answer is 42, isn't it?

Yes - maybe! Some early results from a radio experiment in Cambridge to measure small temperature fluctuations in the cosmic microwave background (the heat left over from the Big Bang) suggests that one of the answers to a puzzling question is 42. The small fluctuations they observed are caused by very large clusters of galaxies as they are first forming. From the information gleaned it is possible to interpret the time it takes for such large things to form, in terms of models of the formation of structure in the Universe. The radio group recently discovered one such early cluster, the analysis of which produced a very uncertain value of the Hubble constant, which is, by chance, 42. However, the uncertainty in this single result is very large. Correctly calculating Hubble's constant is one of the bugbears of modern astronomy. The current consensus concerning its value, considering all ways of measuring it, is that it is somewhere close to 60.

Q Who invented the can-opener, and when?

There are three different dates involved. The first is 1858 when Ezra Warner of Waterbury, Connecticut, invented the can-opener - nearly 20 years after US canners switched from jars to metal cans and almost 50 years after the metal can was invented (1810). Previously, metal cans were opened with general-purpose tools - such as a hammer and chisel! In 1870 William Lyman of W Meridan (also in Connecticut) patented a can- opener that used a wheel for continuous operation, improving on the lever- and-chisel variety. A drawback was that the can had to be pierced in the centre of the lid and the can-opener adjusted to fit each size of can. In 1925 a wheel-type can-opener was patented (we don't know by whom), which rode around the rim of the can on a serrated wheel and was similar to the common type of can-opener that we know today. This was also a predecessor of the electric can-opener as regards its mode of operation. So tin cans were around for a good 50 years before anyone came up with can-openers.

Q What is the weight of Ayers Rock (pictured above) in the Australian Outback?

It's about 10 million to 20 million metric tonnes - an estimate from its shape and density.

Q Why does black coffee fizz when you put the water in, but not when you have sugar in the cup?

If it is freeze-dried coffee, then air pockets get trapped in the coffee grains. Adding water dissolves the coffee and the air in the pockets is released to give a fizz. Sugar must act like anti-bumping granules. These allow bubbles to form more easily and continuously. Without sugar, bubbles are less easily formed, so the air pressure tends to build up until the bubbles burst off and fizz.

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